Synthesis of linear antenna array for 4G mobile communication systems

This paper presents the application of optimization methods for the synthesis of a linear array to operate in the frequency range of 4G technology in Brazil. The desired pattern shall exhibit squared-cosecant shape, so as to provide uniform distribution of power inside the base station cell and to reduce co-channel interference. Such an array is well suited to operate as a radio base station of mobile communications systems. The synthesis is performed by a combination of optimization methods: the genetic algorithm, which is used for the initial global search, and the sequential quadratic programming, which is applied for local refinement of the solution. This approach allows faster convergence than using only one kind of optimization method. The technique is demonstrated for a linear array of isotropic elements and, subsequently, for an array of E-shaped microstrip antennas.